Inlet manifold for internal-combustion engines



Jan. 16, 1968 L. MASSAROTTI 3,363,610

INLET MANIFOLD FOR INTERNAL-COMBUSTION ENGINES 4 Sheets-Sheet 1 Filed April 28, 1965 INVENTOR M MSAROTTI K r jaw 'Attornev Jan. 16, 1968 L. MASSAROTTI 3,

INLET MANIFOLD FOR INTERNAL-COMBUSTION ENGINES 4 Sheets-Sheet Filed April 28, 1965 6 INVENTOR Aiiorney Jan. 16, 1968 MASSAROTTI 3,

INLET MANIFOLD FOR INTERNALv-COMBUSTION ENGINES 4 Sheets-Sheet 5 Filed April 28, 1965 BY :Kart R 38 Attorney Jan. 16, 1968 L, MASSAROfi. 3,363,610

INLET MANIFOLD FOR INTERNAL-COMBUSTION ENGINES Filed April 28, 1965 4 Sheets-Sheet 4 mun-ammo 1mm BY cm 9 Jiiforney United States Patent 3,363,610 INLET MANIFOLD FOR INTERNAL- COMBUSTION ENGINES Luigi Massarotti, Via Melzo 12, Miian, Italy Filed Apr. 28, 1965, Ser. No. 451,482 Claims priority, application Italy, May 9, 1964, 10,131/64; Oct. 15, 1964, 22,130/64 1 Claim. (Cl. 123-52) ABSTRACT OF THE DISCLOSURE An internal-combustion engine, wherein three pairs of cylinders are confrontingly disposed in a first and a second row, and at least one carburetor between the rows is provided with three outlets lying in a row between said first and second rows with a mutual spacing less than the axial spacing of the cylinders of the first and second rows, and a plurality of pipes is provided individual to the cylinders, each of the outlets being connected by two of these pipes to a cylinder of the first row forming part of one pair and to a cylinder of the second row forming part of another pair, the cylinders so connected to a single outlet having pistons in the same relative operating position, the pipes of the central outlet being substantially aligned with one another and the pipes of the remaining outlets forming S-curves between the respective cylinders.

This invention relates to an improved manifold for the supply of gasoline/air mixtures to the cylinders of internal-combustion engines fitted with one or more carburetors. In particular, the improved inlet manifold is suitable for cylinder blocks with 6 or more cylinders (3 or more pairs) in a V-type arrangement for automotive use.

With the inlet manifold of the present invention, the system of feeding the mixture to internal-combustion engines can be improved to give a maximum output, while avoiding the serious troubles which arise with the conventional manifolds, ie the volumetric difference in the mixture between the cylinders which causes power differentials between cylinders, misfire of the engine particularly during acceleration at average speed due to the uneven tenor, vibrations, sudden stresses on the transmission and other defects.

The improved inlet manifold is advantageously applied to feeding systems fitted with one single or double-barrel carburetor, the latter being provided with simultaneous or differentially opening throttles, as well as to feeding systems having two or more single or double-barrel carburetors.

The inlet manifold for feeding the mixture to the cylinders of internal-combustion engines, according to the present invention, is characterized by having separate and independent inlet pipes in a number corresponding to the number of the cylinders of the engine, each inlet pipe being connected to a single cylinder and to a carburetor body or barrel, the connection of said pipes between the carburetor and cylinders being such as to avoid any interference between the intakes of two different cylinders in one single inlet pipe.

The inlet manifold of the invention is further characterised by the fact that each two pipes or pair are connected to a carburetor with, the ends of the pipes of each pair being connected to the cylinders the pistons of which are situated in the same relative position during their reciprocating movement.

By means of this connecting system, during each revolution of the engine (through 360), each carburetor or carburetor barrel alternately feeds two cylinders so that, in the sequence of the engines intake phases during a complete cycle, for every two revolutions of the engine (720) there will be two intakes for each carburetor or carburetor body exactly offset, one from the other, by 360.

This particular arrangement of the inlet pipes of the manifold makes it posible to supply an equal volume of the gas/air mixture to the combustion chambers of the various cylinders, and therefore ensures a balanced running of the engine with consequent considerable increase in output, with greater freedom of acceleration and reduced consumption of fuel.

Some preferred embodiments of the invention are hereinafter described with reference to the accompanying drawing, in which:

FIG. 1 is a partially diagrammatic elevation view of an improved inlet manifold applied to a four-cylinder in-line engine having a double-barrel carburetor;

FIG. 2 is a partially diagrammatic plan view of the manifold shown in FIG. 1;

FIG. 3 is a side view of the manifold shown in FIG. 1;

FIG. 4 is a partially diagrammatic elevation view of a further embodiment of the manifold as applied to a fourcylinder in-line engine provided with a single-barrel carburetor;

FIG. 5 is a partially cut away plan view of the manifold shown in FIG. 4;

FIG. 6 is a diagram showing the rotary movement of the gas flow leaving the carburetor;

FIG. 7 is a diagrammatic illustration of the application of the improved manifold to a six-cylinder in-line engine having a three-barrel carburetor provided with synchronized throttles;

FIG. 8 is a diagrammatic illustration of the application of the improved manifold to .a six-cylinder V-type engine with three carburetors; and

FIG. 9 is a diagrammatic illustration of the application of the improved manifold to a six-cylinder V-type engine with two double-barrel carburetors.

In the system of FIGS. 1-3, the inlet manifold comprises four inlet pipes 1, 2, 3 and 4, of equal length, joined respectively at the ends to form the pairs 1-4 and 2-3. Each pipe is connected to a cylinder, respectively indicated as 1", 2, 3 and 4, of an engine Sfitted with a double-barrel carburetor 6. Numeral 7 indicates the fiange of the double-barrel carburetor 6 in which two noncommunicating holes 8 and 9 are provided, the hole 8 corresponding to the barrel I and the hole 9 corresponding to the barrel II of the carburetor 6. The pair of pipes 2-3, head-joined to form a single duct, is connected to flange 7 at a point corresponding to hole 8 of the body I of the carburetor while the pair of pipes 1-4, similarly joined, is connected to flange 7 at a point corresponding to hole 9 of the barrel II of said carburetor 6. In this way, each barrel of the double-barrel carburetor 6 feeds two cylinders, cylinders 2 and 3 respectively through the pair of pipes 2-3 and cylinders 1 and 4 through the pair of pipes 1-4.

The pipes are connected to the cylinder block of the engine 5 by means of flanges 10 and, in order to have pipes of the same length, the pipes of the pair 1-4 feed the external cylinders 1 and 4 while the pipes of the pair 2-3 feed the internal cylinders 2 and 3 by passing underneath the pipes forming the other pair. The pipes 2 and 3 are further extended as to be connected to the outside hole 8 of flange 7. This arrangement, with a distribution order to cylinders 1-3 4-2, ensures alternating intake between one carburetor barrel and the other at every 180, that is with every half revolution of the engine, while there is no possibility of interference between the intakes of two different cylinders in a single pipe.

With this distribution order, i.e. 1-342, the first intake takes place at cylinder 1 through pipe 1 from carburetor barrel II, the second intake to cylinder 3 takes place through pipe 3 from barrel 1, the third intake to cylinder 4 takes place through pipe 4 from barrel II and the fourth intake to cylinder 2 takes place through pipe 2 from barrel 1.

In the embodiment shown in FIGS. 4 to 6, the four inlet pipes 11, 2, 3 and 4 are led into a single hole 11 of the flange 12 of the single-barrel carburetor 13.

FIG. shows the arrangement of the pipes in the area around the connection to flange 12, while FIG. 6 gives a diagram of the rotary movement forced on the gaseous flow at the exit of carburetor 13 in the sequence of intake phases through the four pipes for the distribution order to the cylinders l34-2.

In the embodiments shown in FIGS. 1 to 6 and above described reference has been made to the application of the improved manifold, according to the invention, to four-cylinder-in-line engines but it is obvious that the same manifold, with simple alterations, can be applied to engines with four horizontally counterposer cylinders.

If the feeding system is fitted with a single-barrel or a double-barrel carburetor, the latter provided with differentially opening throttles, the inlet manifold will be provided with separate inlet pipes connected to a single hole in the carburetor flange and said pipes will be so arranged thataccording to the distribution order to the cylindersthe intakes through the individual pipes will follow one another in a rotary direction so as to cause a rotary movement or vortex in the gaseous column at the exit of the carburetor. With such arrangement of the pipes of the inlet manifold, in addition to the results and advantages above described, there will be a favorable effect in the mixing of the gaseous column.

With particular reference to FIG. 7, the inlet manifold comprises six inlet pipes 101, 102, 103, 104, 105 and 106, of equal length, each connected at one end respectively to cylinders 1, 2, 3, 4, 5 and 6 of engine 107 and, with the other end, to the bodies III-II and I respectively of the three-body carburetor 118, thus obtaining the pairs 101-106, 102-105 and 103-104. The barrels of carburetor 118 are separate one from the other and, therefore, each pair of pipes will be separate from the other pairs. As appears in the diagrammatic cross section of FIG. 7, the pipes of each pair are connected to cylinders whose pistons are situated in the same relative position during their reciprocating movement.

With this arrangement and with a distribution order to cylinders 1-53 6-24, I can achieve an alternating intake between one carburetor body and the other every 120 and, during a complete cycle (720=2 engine revolu- Iutions), there fill be two intakes separated by 360, for each carburetor body or barrel.

With particular reference to FIG. 8, the inlet manifold comprises six feed pipes 101', 102, 103', 104, 105, and 106', of equal length, each connected with one end respectively to cylinders 1, 2, 3, 4, 5 and 6 and, with the other end respectively to carburetors I, II and III, thus forming the pairs of pipes 101106', 102-103 and 104'- 105. As appears in the diagrammatic cross section illustrated in FIG. 8, the pipes of each pair are connected to the cylinders the pistons of which are situated in the same relative position during their alternating movement. Thus each of the carburetor outlets is connected by two pipes to a cylinder of each row and the pipes of the central outlet II are aligned While the pipes 104', 105' and 102', 103' of the other outlets I and III from S-curves,

With this arrangement and with an order of distribution to cylinders 1436-5 2, is achieved an alternating intake between one carburetor and the other of 120 and, during a complete cycle (720:2 engine revolutions), there will be two intakes for each carburetor spaced of 360.

With particular reference to FIG. 9, the inlet manifold comprises eight inlet pipes 101", 102, 103", 104", 105", 106", 107" and 108, of equal length, each connect with one end respectively to cylinders 1, 2, 3, 4, 5, 6, 7 and 8 of the engine 107 and, with the other end, to the bodies I and. II of the carburetor 118 and to the bodies III and IV of the carburetor 118", thus forming the pairs of pipes 101"106", 102103, 104"-107 and 105"- 108. The bodies I, II, III and IV of the double-body carburetors 118' and 118" are separated one from the other and, therefore, each pair of pipes will be separate from the remaining pairs. As appears in the diagrammatic cross section shown in FIG. 9, the pipes of each pair are connected to the cylinders the pistons of which are situated in the same relative position during their alternating movement.

With this arrangement and with a distribution order to cylinders l8-43-657-2, an alternating intake between one carburetor barrel and the other every is achieved so that in a complete cycle (720=2 engine revolutions), there will be two intake strokes separated by 360 for each carburetor barrel.

The invention described and illustrated is believed to admit of any modifications Within the ability of persons skilled in the art, all such modifications being considered within the spirit and scope of the appended claim.

What is claimed is:

1. In an internal-combustion engine, in combination, three pairs of cylinders confrontingly disposed in a first and a second row, carburetor means between said rows provided with three outlets and lying in a row between said first and second rows with a mutual spacing less than the axial spacing of the cylinders of said first and second rows, and a plurality of pipes individual to said cylinders, each of said outlets being connected by two of said pipes to a cylinder of the first row forming part of one pair and to a cylinder of the second row forming part of another pair, the cylinders so connected to a single outlet having pistons in the same relative operating position, the pipes of the central outlet being substantially aligned with one another and the pipes of the remaining outlets forming S-curves between the respective cylinders.

References Cited UNITED STATES PATENTS 1,051,866 2/1913 Delaunay 12352 1,212,478 1/1917 Hall 12352 1,458,481 6/1923 Good l2352 1,512,311 10/1924 Ricardo 123-52 1,985,943 1/1935 Meyer 12352 2,013,737 9/1935 Swan l23--52 2,104,178 l/1938 Anderson 123-52 2,862,490 12/1958 Trisler 123-52 FOREIGN PATENTS 1,111,779 2/1955 France.

WENDELL E. BURNS, Primary Examiner. 

